Normal maps causing speckling

[krogerfoot]

I've gotten some feedback about problems with a scenery I've done the texturing for. Apparently, the normal maps I've included are causing weird output on certain faces. I've tried to figure out what the faces all have in common and made adjustments to the UV maps in Blender and tried to clean up the NRM file as much as possible, but it hasn't solved the problem.

 

I can't reproduce the problem on my comparatively ancient setup, but you can see the effect on the screenshots. Taking out the normal files makes the problem go away.

 

I'm making texture files with Photoshop and using Crazybump to make the normal maps. I've read that this workflow can cause problems with normal maps, but my level of understanding is too rudimentary to make sense of things. Can someone out there tell me what I'm doing wrong and how I should be doing this?

[JohnMAXX]

A couple of things to try.....

 

If there is an alpha layer on the normal map delete it first or make it completly white.....

 

Second and this is another shot in the dark try setting the transparency of the normal to like 20%

 

Also use the superPNG plugin to save the file....

 

A few tricks I learned making urbanMAxx...I dont know if it will help but hey its worth a shot....

[krogerfoot]

Thank you—will give those a try. Alpha layers seemed to me to be a potential source of trouble, but I honestly don't really know what I'm talking about.

 

Love UrbanMAXX, by the way. Thank you for your great work on that.

[Peter T.]

the speckling is caused by the mapping of the object, because those surfaces are not mapped properly (squishing all the surfaces into one pixel, or a column of pixels), the X-Plane could not properly render it that way with normal Maps.

[krogerfoot]

the speckling is caused by the mapping of the object, because those surfaces are not mapped properly (squishing all the surfaces into one pixel, or a column of pixels), the X-Plane could not properly render it that way with normal Maps.

Hi Peter,

 

That's what I thought was going on. Many of the faces where the speckling was occurring were indeed sampling a very limited part of the texture maps, but even after (I think) I fixed this, I was still hearing about the problem. Some of the pictures show enough of the texture to see that the face has more than a few pixels of horizontal and vertical data.

[krogerfoot]

the speckling is caused by the mapping of the object, because those surfaces are not mapped properly (squishing all the surfaces into one pixel, or a column of pixels), the X-Plane could not properly render it that way with normal Maps.

Just in case anyone finds this post on a search for a similar problem, it was remiss of me not to acknowledge that Peter's diagnosis was, in fact, completely correct. I hadn't mapped the textures correctly in Blender. Thank you, Peter.

[SKintheair]

I get some noise too in my objects and I found that during modeling in blender if I have two touching faces from different blender objects or duplicate faces in the same object (typically happens during extrude maneuvers), they create this noise. Most of the times it's solved by deleting hidden duplicate faces (for example a wall from two touching buildings in the plane where they touch) but I don't always get the problem solved. Anyone can confirm or give some hints?